Sri Lanka’s navy killed 26 Tamil Tigers and destroyed four boats during a six-hour sea battle on Monday on the coast just off the sliver of land where the separatists are fighting a final stand, the navy said.

One sailor was killed and three others were injured in the gun duel off of Chalai, north of the military-declared no-fire zone where the Liberation Tigers of Tamil Eelam (LTTE) are dug in among tens of thousands of civilians.

There, the military expects to soon end a 25-year separatist conflict that saw the Tigers at one point controlling 15,000 square km (5,792 sq miles) of the Indian Ocean nation that is now just 25 square km (10 sq miles).

Sri Lanka’s military on Thursday said it has one kilometer left to go before trapping the Tamil Tigers separatists in a no-fire zone, along with thousands of civilians at grave risk in the 25-year war’s final act.

President Mahinda Rajapaksa, under pressure to craft a political deal, has called for a meeting with parliamentarians allied with the Tigers but they have refused until the government resolves the humanitarian crisis faced by civilians trapped in the fighting.

“Now the area is 21 sq km (8 sq miles) and only 1 sq km left other than the safe zone,” military spokesman Brigadier Udaya Nanayakkara said.

As fighting between government troops and Tamil Tiger rebels intensifies in northeast Sri Lanka, calls to spare as many as 180,000 trapped civilians are growing. But in the debate over how far to push a warring government, caution is guiding the international response.

Last week, Secretary of State Hillary Clinton voiced “deep concern” to Sri Lanka over rising civilian casualties in a government-designated no-fire zone. The Red Cross, which normally prefers quiet persuasion to arm-twisting, has raised the alarm over a humanitarian crisis in the remaining pocket of rebel-held territory, where makeshift hospitals are out of needed drugs and food supplies are dwindling.

Sri Lanka’s navy rescued more than 640 people who fled the island’s war zone in a clutch of small boats as Tamil Tiger rebels opened fire, the military said on Wednesday, but tens of thousands remained trapped.

The military has the Liberation Tigers of Tamil Eelam (LTTE) cornered in 28 square km (11 sq miles) of the Indian Ocean island’s northeast, and is battling to deal a final blow to their 25-year separatist rebellion.

At least 18 more rebels were killed in the latest clashes in the shrinking war zone, a military official said on Wednesday.

Tamil Tiger separatists counterattacked with a failed suicide bombing in clashes that killed at least 14 rebels and more than 1,500 refugees fled Sri Lanka’s war zone, the military said on Tuesday.

The suicide bomber, who wore a Sri Lankan military uniform, blew himself up on Monday a few meters from an army frontline in the last town held by the Liberation Tigers of Tamil Eelam (LTTE) in the Indian Ocean island nation’s northeastern corner.

The military, intent on crushing a 25-year rebellion once and for all, says the Tigers are cornered in a shrinking patch of jungle 30 km square (12 sq mile) along with tens of thousands of civilians the LTTE has kept as human shields.

The United Nations said on Monday Tamil Tiger rebels forcibly recruited another of its local workers in Sri Lanka’s war zone along with three dependents of U.N. staff, including a 16-year-old girl.

The United Nations said the forced conscriptions came at the weekend, when nearly 2,000 people fled Sri Lanka’s shrinking war zone as troops fought toward the final showdown in a 25-year war with the separatist Tamil Tigers.

It is the second time the Liberation Tigers of Tamil Eelam (LTTE) have forced a U.N. worker into its ranks. The United Nations and witnesses say hundreds of civilians have been forced to fight or build defenses against a military onslaught.

As the Lankan army prepares to inflict a “decisive blow” to the LTTE guerrillas, the capture of a fertilizer warehouse by the military in the Mullaitivu district has fuelled speculation about the use of chemical weapons in the war zones, officials said today.

At least 14 LTTE guerrillas and three civilians were killed as the army intensified its offensives to capture the remaining pockets of the Tamil Tigers in embattled Northern Sri Lanka, the defence ministry said.